A de novo splice site mutation in CASK causes FG syndrome-4 and congenital nystagmus.

Mutations in CASK cause X-linked intellectual disability, microcephaly with pontine and cerebellar hypoplasia, optic atrophy, nystagmus, feeding difficulties, GI hypomotility, and seizures. Here we present a patient with a de novo carboxyl-terminus splice site mutation in CASK (c.2521-2A>G) and clinical features of the rare FG syndrome-4 (FGS4). We provide further characterization of genotype-phenotype correlations in CASK mutations and the presentation of nystagmus and the FGS4 phenotype. There is considerable variability in clinical phenotype among patients with a CASK mutation, even among variants predicted to have similar functionality. Our patient presented with developmental delay, nystagmus, and severe gastrointestinal and gastroesophageal complications. From a cognitive and neuropsychological perspective, language skills and IQ are within normal range, although visual-motor, motor development, behavior, and working memory were impaired. The c.2521-2A>G splice mutation leads to skipping of exon 26 and a 9 base-pair deletion associated with a cryptic splice site, leading to a 28-AA and a 3-AA in-frame deletion, respectively (p.Ala841_Lys843del and p.Ala841_Glu868del). The predominant mutant transcripts contain an aberrant guanylate kinase domain and thus are predicted to degrade CASK's ability to interact with important neuronal and ocular development proteins, including FRMD7. Upregulation of CASK as well as dysregulation among a number of interactors is also evident by RNA-seq. This is the second CASK mutation known to us as cause of FGS4. © 2017 Wiley Periodicals, Inc.

Simpson-Golabi-Behmel syndrome: an X-linked encephalo-tropho-schisis syndrome. 1988.

INTRODUCTION: The following paper by Professor GiovanniNeri and colleagues was originally published in 1988, American Journal of Medical Genetics 30:287­299. This paper represented a seminal work at the time of publication as it not only reported a new family with a disorder that had been called the "gigantism-dysplasia syndrome", but also suggested naming the condition the Simpson-Golabi-Behmel syndrome. This eponym has clearly stood "the test of time", and that designation is now widely accepted. This paper is graciously republished by Wiley-Blackwell in the Special Festschrift issue honoring Professor Neri. We report on another family with the so-called "gigantism-dysplasia syndrome", an X-linked condition characterized by pre-and postnatal overgrowth, characteristic face with apparent coarseness, dysplastic changes in several tissues, and mild intellectual impairment. This condition has been called the Golabi-Rosen syndrome; however, we agree that is the same entity as that described, in a milder form, by Simpson et al. in 1975 and by Behmel et al. in 1984. Therefore, we suggest that this entity be designated the Simpson-Golabi-Behmel syndrome. The manifestations in affected individuals suggest that this condition represents an X-linked encephalo-tropho-schisis syndrome.

Opitz syndrome is genetically heterogeneous, with one locus on Xp22, and a second locus on 22q11.2.

Opitz syndrome (OS, McKusick 145410) is a well described genetic syndrome affecting multiple organ systems whose cardinal manifestations include widely spaced eyes and hypospadias (Fig. 1). It was first reported as two separate entities, BBB syndrome, and G syndrome. However, subsequent reports of families in which the BBB and G syndrome segregated within a single kindred suggested that they were a single clinical entity. Although the original pedigrees were consistent with X-linked and autosomal dominant inheritance, male-to-male transmission in subsequent reports suggested that OS was inherited as an autosomal dominant trait. Here we report that OS is a heterogeneous disorder, with an X-linked and an autosomal locus. Three families were linked to DXS987 in Xp22, with a lod score of 3.53 at zero recombination. Five families were linked to D22S345 from chromosome 22q11.2, with a lod score of 3.53 at zero recombination. This represents the first classic multiple congenital anomaly syndrome with an X-linked and an autosomal form.

Opitz G/BBB syndrome, a defect of midline development, is due to mutations in a new RING finger gene on Xp22.

Opitz syndrome (OS) is an inherited disorder characterized by midline defects including hypertelorism, hypospadias, lip-palate-laryngotracheal clefts and imperforate anus. We have identified a new gene on Xp22, MID1 (Midline 1), which is disrupted in an OS patient carrying an X-chromosome inversion and is also mutated in several OS families. MID1 encodes a member of the B-box family of proteins, which contain protein-protein interaction domains, including a RING finger, and are implicated in fundamental processes such as body axis patterning and control of cell proliferation. The association of MID1 with OS suggests an important role for this gene in midline development.

Dielectrophoretic growth of platinum nanowires: concentration and temperature dependence of the growth velocity.

The growth velocity of platinum nanowires in an aqueous solution of K(2)PtCl(4) is investigated as a function of the metal complex concentration and temperature. The solution is specially prepared to provide mainly the neutral complex cis-[PtCl(2)(H(2)O)(2)] for growing nanowires by dielectrophoresis. The measured growth velocities indicate diffusion-limited nanowire growth at low concentration and high temperature in qualitative agreement with a theoretical analysis that includes the diffusion of metal complexes and the dielectrophoretic force on the complexes. At concentrations greater than 100 µM and low temperature, different behavior is observed, suggesting the growth rate to be limited by the deposition reaction of platinum at the nanowire tip. The enhancement of the K(+) concentration is found to support nanowire growth. Possible reasons for a rate limitation and for the difference between observed and calculated nanowire growth velocities are discussed.

The cardiofaciocutaneous syndrome.

The cardiofaciocutaneous (CFC) syndrome is a condition of sporadic occurrence, with patients showing multiple congenital anomalies and mental retardation. It is characterised by failure to thrive, relative macrocephaly, a distinctive face with prominent forehead, bitemporal constriction, absence of eyebrows, hypertelorism, downward-slanting palpebral fissures often with epicanthic folds, depressed nasal root and a bulbous tip of the nose. The cutaneous involvement consists of dry, hyperkeratotic, scaly skin, sparse and curly hair, and cavernous haemangiomata. Most patients have a congenital heart defect, most commonly pulmonic stenosis and hypertrophic cardiomyopathy. The developmental delay usually is moderate to severe. The syndrome is caused by gain-of-function mutations in four different genes BRAF, KRAS, mitogen-activated protein/extracellular signal-regulated kinase MEK1 and MEK2, all belonging to the same RAS-extracellular signal-regulated kinase (ERK) pathway that regulates cell differentiation, proliferation and apoptosis. The CFC syndrome is a member of a family of syndromes that includes the Noonan and Costello syndromes, presenting with phenotypic similarities. Noonan syndrome is caused by mutations in the protein tyrosine phosphatase SHP-2 gene (PTPN11), with a few people having a mutation in KRAS. Costello syndrome is caused by mutations in HRAS. The protein products of these genes also belong to the RAS-ERK pathway. Thus, the clinical overlap of these three conditions, which often poses a problem of differential diagnosis, is explained by their pathogenetic relatedness.

Nonsalt-losing congenital adrenal hyperplasia due to 3 beta-hydroxysteroid dehydrogenase deficiency with normal glomerulosa function.

In studies of a 6-yr-old boy and his non-HLA identical 8-yr-old sister, we demonstrated 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) deficiency in the biosynthetic pathways of glucocorticoids and androgens, but not mineralocorticoids. The sister did not manifest abnormal genital development at birth, but developed premature adrenarche at the age of 4 yr, with clitoromegaly and advanced bone age. The brother had perineal hypospadias at birth and developed premature adrenarche at the age of 6 yr. In both siblings, baseline and ACTH-stimulated delta 5 steroids were markedly elevated. The baseline and ACTH-stimulated ratios of delta 5 to delta 4 steroids remained extremely high, and all steroids promptly suppressed with dexamethasone (DEX). Normal baseline PRA and serum and urinary aldosterone (Aldo) levels increased after stimulation with a low Na+ diet. Renal Na+ conservation was normal after dietary Na+ deprivation with and without DEX administration. The PRA to pH 1 Aldo ratio remained normal with normal and low Na+ diets, regardless of DEX administration, indicating normal glomerulosa function with renin stimulation. In both siblings, ACTH increased PRA and Aldo levels, maintaining the PRA to pH 1 Aldo ratio unchanged from the baseline value. In contrast, in control children, PRA was suppressed, while Aldo increased, resulting in a fall of the PRA to pH 1 Aldo ratio. The increase in PRA with exogenous ACTH in these siblings suggests there may be an ACTH-stimulable mineralocorticoid antagonist. During prolonged DEX administration, hCG administration caused a slight increase in 17-hydroxypregnenolone and dehydroepiandrosterone in both the siblings, while testosterone (T) rose poorly in the brother, and estradiol did not rise at all in the sister. These results suggest the possibility of a deficiency of 3 beta-HSD in the gonads as well as the adrenals. After [3H]dehydroepiandrosterone iv infusion, there was normal conversion to [3H]-conjugated testosterone glucuronide, suggesting the presence of normal peripheral 3 beta-HSD activity. We propose that in these siblings, there is a deficiency of 3 beta-HSD in the adrenal zona fasciculata and zona reticularis, whereas 3 beta-HSD activity is intact in the zona glomerulosa. In addition, in these siblings, 3 beta-HSD deficiency was present in the gonads, while peripheral 3 beta-HSD activity appeared to be intact. These cases demonstrate further the heterogeneity of congenital adrenal hyperplasia due to 3 beta-HSD deficiency.

PTPN11 mutations are not responsible for the Cardiofaciocutaneous (CFC) syndrome.

Cardiofaciocutaneous (CFC) syndrome is a multiple congenital anomalies/mental retardation syndrome characterized by congenital heart defects, characteristic facial appearance, short stature, ectodermal abnormalities and mental retardation. It was described in 1986, and to date is of unknown genetic etiology. All reported cases are sporadic, born to non-consanguineous parents and have apparently normal chromosomes. Noonan and Costello syndromes remain its main differential diagnosis. The recent finding of PTPN11 missense mutations in 45-50% of the Noonan patients studied with penetrance of almost 100% and the fact that in animals mutations of this gene cause defects of semilunar valvulogenesis, made PTPN11 mutation screening in CFC patients a matter of interest. We sequenced the entire coding region of the PTPN11 gene in ten well-characterised CFC patients and found no base changes. We also studied PTPN11 cDNA in our patients and demonstrated that there are no interstitial deletions either. The genetic cause of CFC syndrome remains unknown, and PTPN11 can be reasonably excluded as a candidate gene for the CFC syndrome, which we regard as molecular evidence that CFC and Noonan syndromes are distinct genetic entities.

Selected midline defect associations: a population study.

Using data from the population-based Metropolitan Atlanta Congenital Defects Program, the association of seven relatively common and easily ascertainable groups of midline defects was studied. These defects were neural tube defects (575 patients), oral clefts (633 patients), omphalocele (141 patients), esophageal atresia/tracheoesophageal fistula (88 patients), imperforate anus (151 patients), conotruncal heart defects (289 patients), and diaphragmatic hernia (75 patients). Known syndromes were excluded from the analysis. Of 1743 infants with at least one midline defect, 86 (4.9%) had at least a second midline defect, and 9 (0.5%) had two additional midline defects. Pairwise analysis of the seven defects shows that, although most midline defects tend to be statistically associated with other midline defects, specific combinations of midline defects are seen. For example, neural tube defects are more strongly associated with cleft lip with or without cleft palate than with cleft palate alone; imperforate anus is more strongly associated with spina bifida than with anencephaly or encephalocele. Moreover, some combinations of defects are not observed (eg, neural tube defect and conotruncal heart defect, clefts and diaphragmatic hernia, omphalocele and esophageal atresia/tracheoesophageal fistula). These data point to the need for further refinement in the study of the association of midline defects in terms of embryologic and pathogenetic mechanisms because most midline defects tend to occur as an isolated defect, some midline defects occur with nonmidline defects (such as limb defects), and specific associations among midline defects are observed.

The MIller-Dieker syndrome.

Four unrelated children with the Miller-Dieker syndrome, previously referred to as the lissencephaly syndrome, have been evaluated, bringing to ten the number of patients reported with that disorder. We wish to emphasize that lissencephaly is etiologically non-specific and represents only one feature in this malformation syndrome. Other features, such as the craniofacial, neurologic, and growth abnormalities, are more helpful in diagnosing this autosomal recessive disorder.

Bladder retraining. An organized program.

The management of neurogenic bladder dysfunction has been associated with a relatively high incidence of upper urinary tract infections and urosepsis. Today, the regular use of modern diagnostic tools in roentgenology and urodynamics is available. Moreover, contraindications to bladder retraining are better defined, and we have available better methods of evaluating urodynamics, superior reconstructive and corrective urologic surgery, judicious use of intermittent catheterization, and prompt detection and treatment of recurrent bacteriuria. We also know that, with an organized program of bladder retraining and follow-up, a substantial decrease in morbidity of patients with neurogenic bladder dysfunction has become possible.

Total joint arthroplasty: principles and guidelines for postoperative physiatric management.

Postoperative physiatric treatment is an integral part of the replacement of hips, knees, ankles, shoulders, elbows, wrists, and digital joints. Neuromuscular substitution patterns and incoordination usually prevail after joint replacement because of the usual long-term expectation and experience of pain, limitation of motion, fatigue, weakness, and the unavoidable operative trauma. The goals of postoperative physiatric treatment, in line with those of joint replacement surgery, are relief of pain and reestablishment of comfortable, normal neuromuscular functions and their reasonable, safe application in appropriate activities of daily living and of locomotion. By close collaboration between the Department of Orthopedic Surgery and that of Physical Medicine and Rehabilitation, certain principles and detailed protocols of postoperative management have been developed over the last 10 years. These are described in some detail for each of the joint replacements. Optimal results can be achieved only through meticulous attention to physical and psychosocial details, with close cooperation and communication among the involved services and persons.

Cervical fractures and spinal cord injury: outcome of surgical and nonsurgical management.

Data were collected retrospectively for 102 consecutive patients with a cervical spinal cord injury admitted to a spinal cord injury center between 1976 and 1986. Frankel's classification and level of spinal cord injury stayed the same or improved in all patients. The complications that occurred compared favorably with outcomes reported in the literature. Approximately 60% of patients achieved a catheter-free voiding status before dismissal from primary rehabilitation. Patients treated with early surgical stabilization of the cervical column were hospitalized a mean of 21 fewer days than their nonsurgical counterparts. In addition, patients treated with early surgical stabilization achieved their first therapeutic leave of absence from primary rehabilitation approximately 40 days sooner than patients stabilized nonsurgically. At final follow-up, however, no appreciable differences in achievement in activities of daily living and mobility were noted between patients treated with surgical stabilization of the cervical spinal column and those treated nonsurgically.

The Golabi-Rosen syndrome--report of a second family.

Golabi and Rosen (1984) have reported on a new X-linked mental retardation/multiple congenital anomalies (XLMR/MCA) syndrome of pre- and postnatal overgrowth, characteristic "coarse" facial appearance with macrostomia, midline groove of tongue, lower alveolar ridge and lip, submucous cleft of palate, supernumerary nipples, intestinal anomalies, supernumerary pair of ribs, anomalies of sacrum and tailbone, hypoplastic index fingernails, postaxial polydactyly and other digital anomalies. This was an incompletely recessive trait with some manifestations evident in an obligatory carrier. Here we report on a second family (studied at the University of Wisconsin for over 9 years) in which 3 males born to half-sisters and their mother were affected with the Golabi-Rosen syndrome (GRS). Overgrowth was not a prominent manifestation in these affected males. Presence of cystic kidneys, peculiar skin changes and hepatomegaly make it likely that the Golabi-Rosen syndrome is an X-linked MCA/dysplasia/MR syndrome. Its metabolic basis remains unknown. It seems to be an incompletely recessive trait.

RSH/SLO ("Smith-Lemli-Opitz") syndrome: historical, genetic, and developmental considerations.

Thirty years after the publication of Smith et al. [1964: J Pediatr 64:210-217] of 3(4) cases of the RSH/SLO ("Smith-Lemli-Opitz") syndrome and after the publication by Roux [1964: Arch Franç Pédiatr 21:451-464] on the teratogenic action of Triparanol, a defect of cholesterol metabolism was discovered by Tint and his co-workers in the blood of the patients of Irons and Elias [Irons et al., 1993: Lancet 341:1414]. In this manner, the RSH syndrome has been identified as another metabolic multiple congenital anomalies/mental retardation (MCA/MR) syndrome (prototype Zellweger syndrome) in which deficient cholesterol synthesis must be held responsible for all parts of the syndrome, including blastogenetic and organogenetic malformations, minor anomalies, more or less severe abnormalities of CNS and PNS structure and function, postnatal failure to thrive, and, in some cases, stillbirth or infancy/childhood death.

The developmental field concept.

Identical anomalies produced by such different causes as aneuploidy, gene mutation, teratogenic chemicals, and certain surgical procedures show that embryonic primordia respond as units in the production of anomalies of anatomical structure. Hence, they must also act as units during normal ontogeny. The presence of identical malformations in different mammalian species identifies developmental and anatomical homology by virtue of descent from a common ancestor. These dys- and orthomorphogenetically reactive units are the equivalents of the classical experimental embryologist's epimorphic fields, which are those units of the embryo in which the development of complex structures appropriate to the species is determined and controlled in a spatially coordinated, temporally synchronous, and epimorphically hierarchical manner that expresses both species-nonspecific (that is, phylogenetic) and species-specific genetically coded developmental information. Thus, there is some merit in taking a long view of development.

Syndromal (and nonsyndromal) forms of male pseudohermaphroditism.

The term sex determination refers to the genetic events that bring about male or female gonadal development; sex differentiation to all subsequent morphogenetic and physiological events that establish functional sexuality, sexual dimorphism and the secondary sexual characteristics. Virtually all of the steps of sex differentiation are under genetic control; consequently each one of them can fail as result of mutation of the corresponding genes. We shall be concerned with those genes and their mutations that cause pseudohermaphroditism in males and more rarely in females (with the exception of congenital adrenal hyperplasia). Special emphasis will be placed on Swyer, Denys-Drash, RSH, GBBB, campomelic and ATR-X syndromes, whose genes were recently identified.

Comments on biological asymmetry.

Gross forms of asymmetry of biological structure, hence of development, are generally considered abnormalities of conformation with "perfect" symmetry, whether bilateral or radial, being regarded as the "ideal" form. This notion, primarily a cultural deceit of neo-Platonic origin, can easily be shown to be wrong or at best only skin-deep by any student of anatomy or surgery who finds the heart not in the midline but, most of the time on the left, liver on the right, gut coiled and disposed in a certain direction with appendix in the right lower quadrant, and so forth. Indeed, since the beginning of Amphioxus, a major effect of evolutionary developmental modification has been the abolition of the visceral symmetry which characterized this cephalochordate with introduction of a specific pattern of asymmetry called laterality determination. This embryonic process, which is beginning to yield its universal molecular basis, is probably not responsible for another type of biological phenomenon designated fluctuating asymmetry well known to anthropologists (on the basis of quantitative studies of morphometric traits of teeth, appendicular skeleton, dermatoglyphics) and well-known to the ancients who in their most beautiful Hellenistic sculptures introduced deliberate asymmetries into facial structure and expression. Photographic images constructed of 2 right or 2 left facial halves may differ to a starling degree from the authentic face (Fig. 1). The relatively random nature of fluctuating asymmetry makes it less likely to be under strong natural selection. 1 Middle panel: Frontal view of face of a normal man. Left panel: "Artificial" face constructed out of two right halves of the same face. Right panel: Face constructed out of two left halves. A careful study of the right and left panels makes it easier to appreciate the actual degree of asymmetry present in the unaltered middle image/face. However, in addition to laterality determination and fluctuating asymmetry, there are additional forms of biological asymmetry which have other biological bases such as Lyonization, somatic/clonal mosaicism, mosaic aneuploidy/polyploidy, chimaerism, and developmental "resistance" seen with especial clarity in virtually every hereditary limb malformation. In this paper we will attempt to enumerate the causal forms and bases of biological asymmetry.

Sixty years of X-linked mental retardation: a historical footnote.

X-linked mental retardation (XLMR) is a most exciting field of modern medical genetics. It made spectacular advances over the last twenty years, after the advent of molecular genetics. The discovery of the FMR1 gene unraveled the cause of the most common form of heritable mental retardation and provided the prototype of dynamic mutations. New genes continue to be mapped to the X chromosome and more and more are being cloned and characterized, clarifying the nosology of XLMR and, more importantly, adding to our understanding of the mechanisms of intellectual development, normal and abnormal. Looking back to a more or less recent past may provide clues for future discoveries.

Brief historical note: the concept of "gonadal dysgenesis".

The history of gonadal by dysgenesis cautions against overinterpretation of data: The streak gonads are neither the result of dysgenesis nor of embryonic origin but represent late fetal/neonatal degeneration; the X-chromatin-negative character of the buccal smear and the frequency of color vision defects did not indicate male sex in the Ullrich-Turner syndrome but rather an XO constitution; severity of dysgenesis did not correlate with risk of gonadal neoplasia but with genotype; the gonadal lesion in the Ullrich-Turner syndrome was not due to a pituitary defect but a primary ovarian lesion; patients with the Noonan syndrome do not have the Turner phenotype. The concept of gonadal dysgenesis, introduced to Kermauner in 1912, has outlived its usefulness. Improved methods of phenotype analysis, family studies, and endocrine and cytogenetic methods have showen it to be causally and pathogenetically heterogeneous and have contributed to a better identification and delineation of the several different genetic entities which it formerly comprised.